Pavement using layered crushed stone.

In the study of color vision, a MacAdam ellipse is roughly a region on a chromaticity diagram which contains all colors which are indistinguishable, to the average human eye, from the color at the center of the ellipse.

Reginald Alan MacAdam (born March 16, 1952) is a Canadian former professional ice hockey player who spent 12 seasons in the National Hockey League between 1973 and 1985, and was twice selected to play in the NHL All-Star Game.

The Honorable Dr John Macadam (29 May 1827 – 2 September 1865), was a Scottish-Australian chemist, medical teacher, Australian politician and cabinet minister, and honorary secretary of the Burke and Wills expedition.